Flexible Busbar Module Branches for Positional Tolerance Absorption

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Solution Overview

Problem

Conventional busbar modules face challenges in improving followability to busbars, particularly in accommodating positional deviations and manufacturing dispersion, which affects the reliability and efficiency of battery assembly connections.

Innovation Solution

The busbar module incorporates a flexible printed circuit board with stretchable branch portions featuring slits and cuts that allow voltage detection lines to route in a zigzag or meandering pattern, enabling the module to absorb tolerances and follow positional deviations of busbars, thereby enhancing followability and reducing manufacturing complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a rigid circuit board is used, then manufacturing precision is improved, but followability to busbar positional deviations deteriorates

Engineering Contradiction:
Improvecircuit board manufacturing precisionVSAvoidfollowability to busbar positional deviations
Core Design Contradiction:
Manufacturing precisionVSAdaptability or versatility

Solution Approach 1:

The circuit board is divided into a rigid body portion and multiple flexible arm portions. The rigid body portion maintains manufacturing precision and structural stability, while the flexible arm portions can deform to accommodate busbar positional deviations. This segmentation allows different parts of the same circuit board to have different mechanical properties, resolving the contradiction between rigidity for precision and flexibility for adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The circuit board transitions from a completely rigid structure to a dynamic structure with flexible arms that can adapt their shape. The flexible arms are designed to bend and deform within certain limits to follow busbar positional variations, while the body portion remains relatively fixed. This dynamic capability allows the circuit board to maintain both manufacturing precision and adaptability to positional deviations.

Inventive Principle:
Principle #15Dynamics

2Adaptability or versatility

If the circuit body is made stretchable, then followability to busbar is improved, but structural stability deteriorates

Engineering Contradiction:
Improvefollowability to busbarVSAvoidcircuit body structural stability
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The circuit body is segmented into a stable body portion and flexible arm portions. The body portion maintains structural stability and houses the main circuit components, while only the arm portions are designed to be flexible and stretchable. This segmentation ensures that the critical circuit board structure remains stable while the connection arms can adapt to busbar positions.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Different parts of the circuit board have different mechanical qualities. The body portion has high rigidity and stability for structural support, while the arm portions have controlled flexibility for adaptation. This local differentiation of mechanical properties allows the circuit board to simultaneously achieve structural stability and followability to busbars.

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4142037B1Busbar module
Publication Date: 2024.05.15 YAZAKI CORP
  • EP4142037B1 patent drawingFigure 1
  • EP4142037B1 patent drawingFigure 2~3
  • EP4142037B1 patent drawingFigure 4

AI summary

A busbar module (1) includes: a plurality of busbars (2) arranged along a first direction (X) and connected to battery cells; and a plate-like circuit body (3) having a plurality of detection lines (71) to be connected to the busbars and having flexibility, in which the circuit body includes a main line portion (30) in which the plurality of detection lines is routed and branch portions (31), branching from the main line portion and in which the detection lines to be connected to the busbars are routed, the branch portions each include a stretchable portion (34) that is stretchable along the first direction, the stretchable portions each have slits (34a and 34b) or a cutout formed in a direction intersecting the first direction in a plan view of the circuit body, and a detection line of each of the stretchable portions is routed along the slits or the cutout.